This invention relates to the assignment, to each of a plurality of images within different collections in a group of images selected by a search engine, of a position within an order in which the images are to be displayed for presentation to a user.
In the modern age of data storage and communication, search engines are widely used to identify text-based documents meeting selected criteria. Each document has associated textual data called “metadata”, which is typically compiled manually, and the search engine identifies a list of documents corresponding to user-input search terms by matching the search terms to the metadata. Search engine results are presented to the user by displaying a list of the names of the identified documents on a computer monitor or the like. Conventional search engines use algorithms to determine the order in which the identified documents are listed for presentation to a user.
US-A-2002/0123988 describes a known algorithm for ordering a list of text-based documents identified by a search engine in response to input search terms by assigning a score to each document based on usage information. The usage information relates to the number of users that have visited the document.
Image search engines are also used for the sale of products, including the sale of rights in images themselves. For example, photography agencies have benefited from technical advances in digital photography and are able to trade over the Internet as so-called “on-line stock photography agencies”. In particular, photography agencies may offer images (photographs, illustrations, moving images and the like) from a “stock” or “bank” of digital images stored in a database, which may be viewed using a search engine, by potential customers throughout the world. As with conventional search engines, an image search engine performs a search on input textual search terms. Thus, each image has associated textual metadata that is manually input and associated with the image. Such metadata may include the author/photographer name, date, colour or keywords for the subject of the image. Thus the metadata associated with an image is more limited than the metadata associated with documents that are primarily text-based.
An image search engine of an on-line stock photography agency produces the search results by displaying the images to the customer in an arbitrary order, determined by a conventional algorithm designed for searching documents. A typical search for images on user-input each terms may reveal hundreds of images, and so groups of about ten “thumbnail” images are typically shown together to the user as a “page” on screen. However, the customer may need to scroll through large numbers of such groups of identified images in order to find an image that suits his or her needs and, when a suitable image is identified, look at the image in greater detail by enlarging the thumbnail image on screen. This makes image searching time consuming, particularly bearing in mind the ever-increasing numbers of images that may be contained in an agency database.
Furthermore attempts to rank images in the search results for presentation to the customer can lead to bias as between images from the collection of one agency and images from the collection of another agency resulting in both limitation in the choice presented to the customer and restriction on the presentation of images of some agency or under some conditions. In particular this can lead to too many similar looking images being presented to a customer as a result of a search.